In the last section, we went over some basic concepts of the framework
by writing a class that includes static pages. We cleaned up the URI by
adding custom routing rules. Now it’s time to introduce dynamic content
and start using a database.

Instead of writing database operations right in the controller, queries
should be placed in a model, so they can easily be reused later. Models
are the place where you retrieve, insert, and update information in your
database or other data stores. They represent your data.

Open up the application/models/ directory and create a new file called
News_model.php and add the following code. Make sure you’ve configured
your database properly as described here.

This code looks similar to the controller code that was used earlier. It
creates a new model by extending CI_Model and loads the database
library. This will make the database class available through the
$this->db object.

Before querying the database, a database schema has to be created.
Connect to your database and run the SQL command below (MySQL).
Also add some seed records.

Now that the database and a model have been set up, you’ll need a method
to get all of our posts from our database. To do this, the database
abstraction layer that is included with CodeIgniter —
Query Builder — is used. This makes it
possible to write your ‘queries’ once and make them work on all
supported database systems. Add the
following code to your model.

With this code you can perform two different queries. You can get all
news records, or get a news item by its slug. You might have
noticed that the $slug variable wasn’t sanitized before running the
query; Query Builder does this for you.

Now that the queries are written, the model should be tied to the views
that are going to display the news items to the user. This could be done
in our Pages controller created earlier, but for the sake of clarity,
a new News controller is defined. Create the new controller at
application/controllers/News.php.

Looking at the code, you may see some similarity with the files we
created earlier. First, the __construct() method: it calls the
constructor of its parent class (CI_Controller) and loads the model,
so it can be used in all other methods in this controller.
It also loads a collection of URL Helper
functions, because we’ll use one of them in a view later.

Next, there are two methods to view all news items and one for a specific
news item. You can see that the $slug variable is passed to the model’s
method in the second method. The model is using this slug to identify the
news item to be returned.

Now the data is retrieved by the controller through our model, but
nothing is displayed yet. The next thing to do is passing this data to
the views.

The code above gets all news records from the model and assigns it to a
variable. The value for the title is also assigned to the $data['title']
element and all data is passed to the views. You now need to create a
view to render the news items. Create application/views/news/index.php
and add the next piece of code.

Here, each news item is looped and displayed to the user. You can see we
wrote our template in PHP mixed with HTML. If you prefer to use a template
language, you can use CodeIgniter’s Template
Parser class or a third party parser.

The news overview page is now done, but a page to display individual
news items is still absent. The model created earlier is made in such
way that it can easily be used for this functionality. You only need to
add some code to the controller and create a new view. Go back to the
News controller and update view() with the following:

Instead of calling the get_news() method without a parameter, the
$slug variable is passed, so it will return the specific news item.
The only things left to do is create the corresponding view at
application/views/news/view.php. Put the following code in this file.

Because of the wildcard routing rule created earlier, you need an extra
route to view the controller that you just made. Modify your routing file
(application/config/routes.php) so it looks as follows.
This makes sure the requests reaches the News controller instead of
going directly to the Pages controller. The first line routes URI’s
with a slug to the view() method in the News controller.